Tyrell is basically a clone of his father, Garet, and also starts in the same class as him as well. He and Matthew are the only two in the game capable of wielding long swords.

The first adventure is to find and save him from a Psynergy Vortex within Tanglewood after he crashes into the forest with the soarwing. Then the real adventure begins: Tyrell joins at level 4 with 176 experience points and his starting equipment will be a Short Sword, Cotton Shirt, Padded Gloves, and a Leather Cap.

Being a clone of his father, Garet possesses rather low PP ratings, and the lowest agility out of all the characters in Dark Dawn. However, this is offset by his powerful psynergy pool, above-average attack, high HP, and the highest defense rating in the game.

Tyrell is the son of the previous games' Garet, as stated in Japanese-language magazine V-Jump and it is confirmed from press releases that 30 years passed in between Golden Sun: The Lost Age and Golden Sun: Dark Dawn and that the main characters of the game are the children of the main characters from the previous games. It's interesting to note that while Tyrell has a similar build, hair style, and hair color to Garet, his light blue/green eye color is much different from Garet's auburn eye color.

Tyrell is fearless, having a poor sense of danger. This, mixed with pride and curiosity, causes the hunt for the Roc's Feather and frustrates the party along the way, especially Karis (even causing her to cry at one point). Throughout Dark Dawn, he accepts and creates unneccessary challenges, such as challenging Blados immediately after fending off an ambush. Thanks to his mouth, even the calmest foes can't resist targeting him first. When Tyrell does get hurt, he hardly acknowledges it.